Improved crank-connection in double-piston steam-engines



NITED STATES i PATENT OFFICE.

JOHN SMITH, OF CINCINNATI, OHIO.

IIVIPROVED CRANK-CONNECTION IN DOUBLE-PISTON STEAM-ENGINES.

` Specification forming part of Letters Patent No. 12,187, dated January 72, 1855.

.To @ZZ whom, it may concern:

Beit known that I, Jol-IN SMITH, of Cincinnati, in the county of Hamilton and State of Ohio, have invented anew and useful Improvement in Steam-Engines; and I do hereby declare that the following is a full, clear, and exact description of the same, referencebeing had to the annexed drawings, making a part of this specification, in whieh- Figure l is a longitudinal section of astcamcylinder, the pistons within it not being bisected. Fig.2 is a transverse section of the same.

Similar letters of reference indicate corresponding parts in the two figures.

Thisinvention relates to an improvement in reciprocatingsteam-engines5 Aand it consists in having two pistons within a cylinder, said pistons being connected with a crank, as will be hereinafter shown, so that the pistons act directly upon it without the intervention of a piston and connecting rods, and transmit the power of the steam directly to the driving or crank shaft.

A represents a steameylinder provided with the usual slide-valve, and B B are two pistons which are connected by a cross head or plate, O, which is sufficiently long to allow a requisitedistance or space between the two pistons.

At about the center of the cross head or plate O there is a vertical slot, D, in which the crank E fits, said crank being on a shaft, F, which passes transversely through the cylinder, as shown in Fig. 2. The steam is admited alternatelyinto the ends ofthe cylinder A 'and acts against the outer faces of the pistons forth the crank E is turned and a rotary motion given the shaft F.

By the above improvementthe ordinary piston and connecting rods are dispensed with, the pistons being connected directly with the crank. The engine is economical to Inanufac` ture, having but few parts, and works well in practice.

The pistons B B and cross head or plate C may be composed of one casting. The steam is admitted into the ends of the cylinder and exhausted or allowed to escape in the usual manner, there being no peculiarity in the construction of the valve,which, as before stated, is the ordinary slidevalve.

I do not claim the employment of two pistons within a cylinder separately; but

What I do claim as new, and desire to secure by Letters Patent, is-

rIhe employment or use of two pistons, B B, connected by a cross head or plate, C, which has a slot, D, through it, in which the crank E of the shaft F ts,whereby the pistons are directly connected to the crank, and a rotary motion given the crank-shaft without the intervention ofthe usual piston and connecting rods, as herein shown.

JOI-IN SMITH.

Vitnesses:

W. L. NnwrLL, N. MARCHANT. 

